using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Linq.Expressions;
using System.Runtime.Remoting.Contexts;
using System.Security.AccessControl;
using System.Security.Policy;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace ytdlp_gui
{
    public partial class Download : Form
    {
        public Download(YTdlpProcess process, string workdir, string convert_to)
        {
            this.process = process;
            this.workdir = workdir;
            this.convert_to = convert_to;
            InitializeComponent();
        }

        private async void Download_Load(object sender, EventArgs e)
        {
            process.Start += (_sender, start_event) =>
            {
                lblDownload.Text = String.Format(
                    "Connecting to %s...",
                    start_event.provider
                );
            };

            process.Error += (_sender, error_event) =>
            {
                MessageBox.Show(this, error_event.error, "yt-dlp error", MessageBoxButtons.OK, MessageBoxIcon.Error );
                this.Close();
            };

            process.Progress += (_sender, prog_event) =>
            {
                int progress = (int)(prog_event.progress * 100 + 0.5);
                this.Text = String.Format(
                    "Downloading {0}/{1} {2}% - {3}",
                    prog_event.playlist_current,
                    prog_event.playlist_total,
                    progress,
                    prog_event.file
                );
                lblDownload.Text = this.Text;
                pbDownload.Value = progress;
            };

            process.Finished += (_sender, finish_event) =>
            {
                Regex regex = new Regex(@"^(.+)\s\[[\w-]+\](\.[\w.]+)$");
                Match match = regex.Match(finish_event.file);

                if (!match.Success)
                {
                    MessageBox.Show(this, "Could not find the file we just downloaded...", "Uhhh...");
                    this.Close();
                }

                string newFile = match.Groups[1].Value + match.Groups[2].Value;

                string filePath = Path.Combine(workdir, finish_event.file);
                string newFilePath = Path.Combine(workdir, newFile);

                if (File.Exists(newFilePath))
                    System.IO.File.Delete(newFilePath);

                if (convert_to == null || Path.GetExtension(filePath) == convert_to)
                {
                    System.IO.File.Move(filePath, newFilePath);
                    System.IO.File.SetLastWriteTime(newFilePath, DateTime.Now);
                }
                else
                {
                    newFile = Path.ChangeExtension(newFile, convert_to);
                    newFilePath = Path.ChangeExtension(newFilePath, convert_to);
                    FFmpegProcess convertion = (new FFmpeg()).Convert(filePath, newFilePath);

                    convertion.Progress += (_ffmpeg, prog_event) =>
                    {
                        int progress = (int)(prog_event.progress * 100 + 0.5);
                        // this.Text = "Converting - " + progress.ToString() + "%";
                        lblConvertion.Text = String.Format(
                            "Converting {0}/{1} {2}% - {3}",
                            convertion_current,
                            convertion_total,
                            progress,
                            newFile
                        );
                        pbConvertion.Value = progress;
                    };

                    convertion.Finished += (_ffmpeg, _ffmpeg_e) =>
                    {
                        System.IO.File.Delete(filePath);
                        triggerConvertionQueue();
                    };

                    convertion_queue.Enqueue(convertion);
                    convertion_total += 1;
                    triggerConvertionQueue();
                }
            };

            // Can run in background :)
            _ = await process.Run();
        }

        private void btnCancel_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void Download_FormClosing(object sender, FormClosingEventArgs e)
        {
            process.Cancel();
            foreach (FFmpegProcess conversion in convertion_queue)
                conversion.Cancel();
        }

        protected async void triggerConvertionQueue()
        {
            if (converting)
                return;

            if (convertion_queue.Count() == 0)
                return;

            converting = true;
            convertion_current += 1;
            await convertion_queue.Dequeue().Run();
            converting = false;
        }

        protected readonly YTdlpProcess process;
        protected int convertion_current = 0;
        protected int convertion_total = 0;
        protected Queue<FFmpegProcess> convertion_queue = new Queue<FFmpegProcess>();
        private bool converting = false;
        protected readonly string workdir;
        protected readonly string convert_to;
    }
}